Conventionally, there is a known electric storage device such as a secondary battery which can be charged and discharged. The electric storage device includes an electrode assembly formed by layering positive electrodes and negative electrodes with separators interposed therebetween and a case housing the electrode assembly. Among electric storage devices of this type, as shown in FIG. 8, there is one in which a case 101 has a substantially rectangular parallelepiped external shape capable of housing an electrode assembly 102 inside itself and paired side walls 101a, 101a forming the case 101 have a plurality of convex parts 104, 104, . . . protruding toward an inside of the case 101 (JP-A-62-126566).
In such an electric storage device 100, the convex parts 104 press substantially the entire electrode assembly 102 toward an inner side in a layered direction at predetermined pressure to narrow intervals between the adjacent electrodes 103 in substantially the entire electrode assembly 102. As a result, charge-discharge efficiency of the electric storage device 100 is enhanced.